What is the best graphics accelerated video encoder that can batch process?

I'm pretty sure that Handbrake has some hardware acceleration options, and it's batch processing is great. You mentioned DVDFab, so I'm guessing you're talking about ripping DVDs to m4v. If that's the case, you'd still have to use a program like DVDFab to decrypt the discs, then you could batch a bunch of discs with Handbrake.

I actually don't want rip to m4v. I want to rip to a format that supports AC3. I've played back avi's with AC3 on them. I wish sony would better realize their potential with the ps3 playback capabilities and give us mkv + m4v support!